Diffraction spikes in newts

[andrew s]

2 hours ago, JeremyS said:

It’s not just the diffraction spikes you have to worry about.

Just because you don't have a reflection in a mirror @JeremyS is no reason to dislike Newts 😅 

Regards Andrew 

[Ratlet]

2 minutes ago, andrew s said:

Just because you don't have a reflection in a mirror @JeremyS is no reason to dislike Newts 😅 

Regards Andrew 

Wouldn't that be great?  Presumably if your head isn't causing a reflection, then you wouldn't interfere with the light path.  You could replace the secondary with an eyepiece.  You could do visual with a RASA at F2!

 

[andrew s]

Just now, Ratlet said:

Wouldn't that be great?  Presumably if your head isn't causing a reflection, then you wouldn't interfere with the light path.  You could replace the secondary with an eyepiece.  You could do visual with a RASA at F2!

 

Yes but becoming a Vampire is a high price to pay 🧛‍♂️🦇 Regards Andrew 

[Ratlet]

7 minutes ago, andrew s said:

Yes but becoming a Vampire is a high price to pay 🧛‍♂️🦇 Regards Andrew 

I already work lots of night shift.  Does anyone know the carrying capacity of a bat?  Would be dead easy to get to a dark sky site.  

Ooh, but I'd have to give up garlic and replace it with neds.  Pretty sure if I tried snacking on some of the locals who are out after dark round me I'd fail a drugs test at work.

Swings and roundabouts eh?

[John]

There have been a few newtonians where the secondary mirror was positioned away from the optical axis of the primary mirror, on the side of the tube. Off-axis newtonians. No secondary support vanes of course. Here is a review of a DGM 5.5 inch off-axis dob by Ed Ting:

Telescope Reviews, Page 7

It impressed the reviewer but there are a number of drawbacks with the design (cost being one of them).

Orion (USA) even had one in their catalogue for a while but the design was not popular so it didn't last.

I imagine that collimation is an interesting process 🤔

 

Edited March 10 by John